1. Field of the Invention
This invention relates to a process of fabricating a color display panel, and more particularly to a process of fabricating a color display panel that is adapted to form transparent electrodes and transparent conductive films in a plasma display panel.
2. Description of the Related Art
Generally, a plasma display panel(PDP) radiates a fluorescent material (or phosphor) by an ultraviolet with a wavelength of 147 nm generated during a discharge of He+Xe or Ne+Xe gas to thereby display a picture including characters and graphics. Such a PDP is easy to be made into a thin film and large-dimension type. Moreover, the PDP provides a very improved picture quality owing to a recent technical development. The PDP is largely classified into a direct current (DC) driving system and an alternating current (AC) driving system.
The PDP of AC driving system is expected to be highlighted into a future display device because it has advantages in the low voltage drive and a prolonged life in comparison to the PDP of DC driving system. Also, the PDP of AC driving system allows an alternating voltage signal to be applied between electrodes having a dielectric layer therebetween to generate a discharge every half-period of the signal, thereby displaying a picture. Since such an AC-type PDP uses a dielectric material, the surface of the dielectric material is charged with electricity. The AC-type PDP allows a memory effect to be produced by a wall charge accumulated to the dielectric material due to the discharge.
Referring to FIG. 1, the AC-type PDP includes a front substrate 1 provided with a sustaining electrode pair 10A and 10B, and a rear substrate 2 provided with an address electrode 4. The front substrate 1 and the rear substrate 2 are spaced in parallel with having a barrier rib 3 therebetween. A mixture gas such as Ne-Xe or He-Xe, etc. is injected into a discharge space defined by the front substrate 1 and the rear substrate 2 and the barrier rib 3. The sustaining electrodes 10A and 10B consist of transparent electrodes 6A and 6B and metal electrodes 7A and 7B. The transparent electrodes 6A and 6B are usually made from Indium-Tin-Oxide(ITO) and has an electrode width of about 300 .mu.m. Usually, the metal electrodes 7A and 7B take a three-layer structure of Cr--Cu--Cr and have an electrode width of about 50 to 100 .mu.m. These metal electrodes 7A and 7B play a role to decrease a resistance of the transparent electrode 6 with a high resistance value to thereby reduce a voltage drop. Such sustaining electrodes 10 make a pair by two within a single plasma discharge channel. Any one of a pair of sustaining electrode 10 is used as a scanning/sustaining electrode that responds to a scanning pulse applied in an address interval to cause an opposite discharge along with the address electrode 4 while responding to a sustaining pulse applied in a sustaining interval to cause a surface discharge with the adjacent sustaining electrodes 10. A sustaining electrode 10 adjacent to the sustaining electrode 10 used as the scanning/sustaining electrode is used as a common sustaining electrode to which a sustaining pulse is applied commonly. A distance a between the sustaining electrodes 10 making a pair is set to be approximately 100 .mu.m. On the front substrate 1 provided with the sustaining electrodes 10, a dielectric layer 8 and a protective layer 9 are disposed. The dielectric layer 8 is responsible for limiting a plasma discharge current as well as accumulating a wall charge during the discharge. The protective film 9 prevents a damage of the dielectric layer 8 caused by a sputtering generated during the plasma discharge and improves an emission efficiency of secondary electrons. This protective film is usually made from MgO. Barrier ribs 3 for dividing the discharge space is extended perpendicularly at the rear substrate 2, and the address electrode 4 is formed between the barrier ribs 3. On the surfaces of the barrier ribs 3 and the address electrode 4, a fluorescent layer 5 excited by a vacuum ultraviolet lay to generate a visible light is provided.
Further, the AC-type PDP includes a color filter 12 provided at the front surface of the front substrate 1. The color filter 12 is added with a red, green or blue pigment to transmit only a specified wavelength of light, thereby improving the color purity. The color filter 12 may include a function of shielding an electromagnetic wave. To this end, the color filter 12 is mixed with a conductive mash, and is grown with a transparent conductive film using a vacuum deposition technique. The transparent conductive film is usually made from ITO and is entirely deposited on the front substrate 1. The color filter 12 or the transparent conductive film having a function of shielding an electromagnetic wave is connected to a ground voltage source GND.
As shown in FIG. 3, the PDP 20 has mxn discharge pixel cells 11 arranged in a matrix pattern. At each of the discharge pixel cells 11, scanning/sustaining electrode lines Y1 to Ym, common sustaining electrode lines Z, and address electrode lines X1 to Xn are crossed with respect to each other. The scanning/sustaining electrode lines Y1 to Ym and the common sustaining electrode lines Z consist of the sustaining electrode 10A and 10B making a pair. The address electrode lines X1 to Xn consist of the address electrode 4.
However, the conventional PDP has a difficulty in that the conductive mash must be uniformly mixed when the conductive mash is added to the color filter 12, and has a problem in that a fabrication cost rises due to the conductive mash that is a separate additive. Also, it has problems in that a fabrication cost rises because the transparent conductive material formed on the conventional PDP is deposited using the vacuum sputtering technique, and that a resistance is increased because the transparent conductive film deposited at a low temperature is oxidized at the time of a firing of a dielectric layer requiring a high-temperature heat treatment. Moreover, it has a problem in that a bubble is left in the transparent conductive film formed in the post process due to a bubble generated upon oxidation of the transparent conductive film.